It is known that rod-like molecules having certain axial ratios (molecular length/diameter) show liquid crystalline states depending on densities. This phenomenon itself is a universal physical phenomenon controlled by thermodynamics, and it does not depend on materials and compositions of rod-like molecules. Generally, rod-like molecules self-assembled by a thermodynamic driving force have a domain structure. Examples of such rod-like molecules include inorganic semiconductor lots (see, for example, Non-Patent Document 1), carbon nanotubes (see, for example, Non-Patent Document 2 and 3), virus molecules such as bacteriophages (see, for example, Non-Patent Document 4), and the like.
In recent years, as large-scale integrated circuits (LSI) have become finer, a technique for processing of even finer structures has been required. To meet such a requirement, a domain structure formed by self-assembled rod-like molecules can be utilized to easily process fine structures in nano-sizes.
For example, zinc oxide is a useful semiconductor material for chemical sensors, solar cells, transistors, nanodevices such as carbon nanotube composite field emission devices and the like, and it is disclosed that a domain formation by self-assembled tobacco mosaic viruses (TMV), which are rod-like nanomolecules, can be used for forming a one-dimensional nanostracture, such as a nanowire of zinc oxide and the like (see, for example, Non-Patent Document 5).
When forming a domain structure by self-assembled rod-like molecules, it is difficult to control molecular directions between domains. To direct rod-like molecules to a certain direction, for example, a method for self-organizing TMV to a uniaxial direction by controlling an evaporation speed of a solvent of a TMV-dispersed solution (see, for example, Non-Patent Document 6), and a method for increasing a uniaxial orientation with a capillary force that is generated by drying a solvent of a TMV-dispersed solution in a capillary tube (see, for example, Non-Patent Document 7) have been disclosed.